1. Field of the Invention
The present invention relates to a method for forming miniature contacts of highly integrated semiconductor devices, and more particularly to a method for forming miniature contacts of highly integrated semiconductor devices capable of being applied to DRAMs, SRAMs and ASICs.
2. Description of the Prior Art
An increase in the integration degree of highly integrated devices results in a decrease in the area per cell. Such a decrease in the area per cell also results in a decrease in design rule and a decrease in space between neighboring lines. As a result, it is required to use a method for forming a direct contact between lines.
As a conventional contact forming method, a method for forming contacts in a self-aligned manner has been used. However, this method encounters a difficulty in performing an etching step using a contact mask, since the aspect ratio upon etching contacts becomes high at a severe topology. Moreover, this method involves problems of short circuits between word and bit lines and between and the word or bit line and a storage capacity electrode, other short circuits of lines caused by terminals, a poor step coverage, and an increase in resistance. Consequently, it is difficult to obtain a process margin in manufacture of semiconductor devices.